Mendikoa I.,University of the Basque Country | Sanchez-Lavega A.,University of the Basque Country | Perez-Hoyos S.,University of the Basque Country | Hueso R.,University of the Basque Country | And 6 more authors.Publications of the Astronomical Society of the Pacific | Year: 2016

Vibratory dynamics of variable geometry trusses (VGT) is studied and a tool is developed to efficiently estimate the dynamic properties of VGTs throughout their movement. A procedure for estimating the variation of natural frequencies and vibration modes of VGTs during their movement, making it unnecessary to recalculate them at all positions but just for a small number thereof, is presented. To calculate the derivatives of modes and frequencies, the stiffness matrix derivatives are calculated with respect to the nodal coordinates. To model the variations of frequencies and modes throughout VGT evolution, linear estimation is used, which obtains natural frequencies and vibration modes in a new position from their values in a previous position. The derivatives of the natural frequencies and vibration modes are calculated in relation to the nodal coordinates for a reference position.